Surface soil salinity, hydroperiod, and in situ soil reflectance datasets for coastal wetlands at Carpinteria Salt Marsh Reserve (USA) and Langebaan Lagoon (South Africa)

This dataset collection supports a study evaluating a transferable imaging spectroscopy approach for mapping surface soil salinity in coastal wetlands and for relating salinity patterns to hydroperiod. The data include: (1) in situ soil reflectance and soil salinity survey measurements collected at the Carpinteria Salt Marsh Reserve (California, USA), used for calibration and validation of a soil salinity retrieval model; (2) imaging spectroscopy–derived surface soil salinity raster products for the Carpinteria Salt Marsh Reserve and Langebaan Lagoon (Western Cape, South Africa); and (3) hydroperiod raster products for both sites derived from Sentinel-1 synthetic aperture radar time series, representing the percentage of time each pixel was inundated over the observation record.The Carpinteria in situ dataset consists of field spectrometer visible–shortwave infrared reflectance measurements paired with soil samples processed to estimate dry-basis surface soil salinity. These observations were used to develop a Partial Least Squares Regression (PLSR) model for predicting surface soil salinity from soil reflectance. The raster salinity products represent application of this retrieval framework to airborne imaging spectroscopy data (AVIRIS-3 for Carpinteria and AVIRIS-NG for Langebaan) within soil-dominated pixel domains. The hydroperiod rasters were generated independently and are included to enable analysis of hydrologic controls on spatial salinity patterns.These datasets provide the spatial products needed to analyze coastal wetland surface soil salinity, hydroperiod–salinity relationships, and the transferability of imaging spectroscopy-based soil salinity retrieval across contrasting wetland systems.